How to register a property group in blender 2.8
Check the source

As with a lot of blender, can check the code for bpy.utils.register_classes_factory

def register_classes_factory(classes):
    """
    Utility function to create register and unregister functions
    which simply registers and unregisters a sequence of classes.
    """
    def register():
        from bpy.utils import register_class
        for cls in classes:
            register_class(cls)

    def unregister():
        from bpy.utils import unregister_class
        for cls in reversed(classes):
            unregister_class(cls)

    return register, unregister


As you can see it does no more than register unregister classes.  (Notice the reversing of list in unregister)

I would recommend using your own register methods. Even prior, would recommend own register methods over the now defunct bpy.utils.register_module()

To still use the factory, in conjunction with your own methods. 

foo, bar = bpy.utils.register_classes_factory(classes)

def register():
    foo()
    # do other stuff


etc.  Or write your own factory that also takes type, property pairs.